In general, a vehicle seat sliding apparatus includes an upper rail that supports a seat thereabove, and a lower rail that supports the upper rail in a relatively movable manner. Also, in many seat sliding apparatuses, a locking mechanism that is capable of regulating the relative movement of the upper rail with respect to the lower rail is disposed as well. Further, configurations in which an unlock operation of the locking mechanism caused by a collision load is prevented by an unlock operation prevention mechanism disposed have been proposed.
For example, JP 2-126937UM-A (Reference 1) discloses an unlock operation prevention mechanism that has a blocking member which is moved forward based on the collision load during a forward collision of a vehicle. The blocking member that is moved forward regulates a rotation of a lock member so that the unlock operation of the locking mechanism is regulated.
Also, during the forward collision of the vehicle, the collision load causes a posture of a passenger in the seat to be changed. For example, JP 2011-213195A (Reference 2) discloses a method for correcting a sitting posture of the passenger with an airbag disposed in a seat cushion, in which a deployment pressure of the airbag is used to lift a bearing surface.
In other words, as shown in FIG. 22, the sitting posture of the passenger is in a state where the hands and feet thereof are extended to be thrown forward by inertia during the forward collision. In this case, a bearing surface 120s and the thigh of the passenger are lifted as shown in FIG. 23 if an airbag 121 that is disposed in a front portion side of a seat cushion 120 is deployed. In this manner, the feet are in an upright state to provide against an input of the collision load. In other words, the sitting posture is corrected into a posture with which a seat belt 123 that is disposed in the seat 122 and an airbag (not shown) for passenger protection deployed in front of the passenger function more effectively.
However, in a seat sliding apparatus 125, the deployment pressure of the airbag 121 that is disposed in the seat cushion 120 acts in a direction in which an upper rail 126 thereof is pushed downward to a lower side. In this manner, the upper rail 126 is bent and the locking mechanism thereof (not shown) ends up in the unlock operation.
In other words, in many seat sliding apparatuses, the locking mechanism can be unlock-operated when an operation lever 127 that is arranged in front of the seat 122 is pulled up. As such, a case where a front portion of the upper rail 126 is bent downward and a position of the operation lever 127 is in an unchanged state as shown in FIG. 23 is substantially equivalent to a state where the operation lever 127 thereof is pulled up. A timing at which the upper rail 126 is bent by the deployment pressure of the airbag 121 may not be consistent with a timing at which the unlock operation prevention mechanism using the above-described collision load is operated, and thus there is room for improvement with regard to this point.